1. Field of the Invention
The present invention relates to full thickness resection devices for performing localized resections of lesions in body organs, particularly gastric lesions.
2. Description of the Related Art
A resection procedure involves excising a portion of an organ, approximating the surrounding tissue together to close up the hole created by the excision, and removing the excess tissue. Various conventional devices and procedures are known for resectioning lesions in body organs, however, known resection devices suffer deficiencies. Some of these deficiencies with known devices include: the lack of a capability to view the lesion within the body and to grasp the lesion to position the lesion within the resection device; they require abdominal wall penetrations; and they have sizes and structures, e.g., rigid rather than flexible, that are not desirable.
As mentioned above, many known resection devices and procedures require at least one incision in an area near the portion of the organ that is to be excised. This incision may be required to allow the physician to gain access to the lesion, to view the lesion during the procedure, and to provide an opening in the body cavity large enough such that the surgeon is able to perform all of the required steps of the procedure with all of the variety of different surgical instruments required. It is not desirable to require an incision for performing the resection procedure. When an incision is required, the patient must receive general anesthesia, and thus, the procedure cannot be performed on an outpatient basis which would require only conscious sedation. Additionally, the incision results in pain for the patient during the recuperation period and may involve a partial or entire loss of mobility while recuperating from the incision. Thus, the time required to recover from such a procedure is often longer than for procedures which do not require incisions.
To attempt to overcome some of the deficiencies noted above, a known resection device includes an endoscope and a surgical stapling and cutting apparatus for resectioning lumenal tissue. Whereas this device may obviate the requirement for percutaneous access to the lesion site, drawbacks exist with this resection device, particularly if utilized for excision of gastric lesions. The resection device includes a circular, or semi-circular, stapling instrument. Whereas circular stapling devices are useful for resectioning tubular organs, such as a colon, they have deficiencies if used for resectioning gastric lesions.
Circular staplers are optimally suited for resectioning tubular organs, such as the colon. The colon is comprised of a generally tubular, thin-walled structure. When a section of tissue is removed from the wall of the tubular organ, the circularly-shaped stapler is best-suited for joining the curved wall surfaces that define the hole in the wall that results when the tissue section is removed. By positioning the staples in a circular orientation in the tubular wall structure, when contrasted with positioning the staples in a linear orientation, a minimal obstruction will result within the internal smooth bore of the tubular organ.
However, it is not advantageous to utilize a circularly-shaped resection device for resectioning gastric lesions. The walls of the stomach are formed much differently than those of tubular organs. Whereas the tubular organs are generally thin-walled structures, the stomach is generally formed by thick-walled, multi-layered, flat, muscle tissue. Resectioning of the stomach is generally accomplished by removing a three-sided wedge-shaped portion of the stomach wall. Three linear cuts are made in the stomach wall to form the wedge portion to be removed and, thus, it is desirable to staple the stomach wall along the same axes as those on which the cuts were made. This cannot be accomplished if a circular stapler is utilized. Circular staplers are limited by the area circumscribed by the circular area within the staple/line cut. Utilizing a circular stapler to resection tissue that is linearly cut would be akin to utilizing a circular hole punch to cut-out a triangular wedge shape in a piece of paper rather than utilizing scissors to cut the wedge shape. Utilizing a linear stapler would give the freedom to remove much larger areas via a series of extended cuts.
Additionally, if a circular stapler was used to resection the gastric wall, positioning of the stapler would be difficult. Circular staplers are generally orientated within the resection device around a center post. If a circular stapler was used to resection tissue on the generally flat wall of the stomach, to properly position the stapler around the lesion, the center post would contact, and thus possibly puncture, the lesion. This is not clinically desirable and could result in complications for the patient. Thus, whereas a circular stapler resectioning device may obviate the requirement for an incision when performing resectioning procedures on tubular organs, the device has drawbacks, particularly if utilized to resection gastric lesions.
An additional problem with known resection devices is difficulty in properly positioning the tissue to be removed within the device. This problem is particularly apparent in procedures involving the gastric wall. As stated above, the gastric wall comprises thick, multi-layered, muscle tissue. This is in stark contrast to the generally thin-walled tubular organs. Thus, the stomach tissue is much more difficult to draw into the resection device than is the tissue of tubular organs.
In order to draw the tissue into the resection device, many known procedures require the use of a separate tool(s) to grasp the tissue and position it within the resection device. This has the obvious drawbacks of requiring the physician to insert and utilize a separate tool(s) for grasping and manipulating the tissue. This results in additional complexity for the procedure and may require a larger incision, or multiple incisions, into the patient so that the ancillary tool(s) may be inserted into the patient's body.
Even if a grasper tool is incorporated into a resection device, such known resection devices, even if they could be utilized to cut and staple the stomach tissue, would not able to adequately position the uniquely difficult gastric wall within the device. The grasper most probably is not structurally sufficient to manipulate the more difficult to maneuver thicker gastric wall. Additionally, in a colonic procedure with a circular stapler, the pulling direction may be parallel to the stapler axis. However, in a gastric procedure, it is not desirable that the pulling direction be parallel to the staple line since this could create wrinkles of tissue in the edges of the linear staple line.
Therefore, it would be desirable to provide an improved method and apparatus for performing localized resections of lesions in body organs, particularly gastric lesions.